Ore-concentrating agitator.



No. 656,674. Patented Aug. 28, I900.

A. H. STEBBINS.

ORE CONCENTRATING AGITATDR.

(Application filed Oct. 2, 1899.) (No Model.) 2 'Sheets$heet l.

No. 656,674 Patented Aug. 28, I900. A. H. STEBBiNS. ORE CONCENTRATI'NGAGITATOR;

(Application filed Oct. 2, 1899.)

2 Sheets8heat 2. S

(No Model.)

Uwrrnn S rains PATENT OrrrcEE,

ALBERT H. STEBBINS, OF LITTLE ROCK, ARKANSAS.

GRE-CONCENTRATING AGITATOR.

SPECIFICATION forming part of Letters Patent No. 656,674, dated August28, 1900,

Application filed October 2, 1 8 9 9.

To all whom it may concern:

Be it known that I, ALBERT H. STEBBINS, a citizen of the United States,residing at Little Rock, county of Pulaski, State of Arkansas, haveinvented certain new and useful linproveinents in Ore-ConcentratingAgitators, of which the following is a specification.

My invention relates to ore-concentrating agitators in which finelydivided or comminuted ore is subjected to the action of an airblasttopartly separate the heavy from the light particles and to carry theremainder into a settling-chamber, where the air-currents, beingreduced, allow the heavy particles to settle under the action of gravityand fall into appropriate chutes, while the lighter waste material iscontinued onward by the reduced air-currents and carried out of themachine. It is necessary in this character of machine to make it ofpractical value that it shall be of large capacity-that is, it mustefficiently separate a large quantity of ore or metal from itsaccompanying impurities-and this is particularly so when dealing withthe less rich ores. In order to secure this efficiency, it is notsuflicient to merely increase the air-blast alone as the greaterquantity of material is fed to the machine, as this results in carryingthe mass bodily into the separating-chamber above, destroying thecharacter of the currents therein necessary for the settling process,and carrying much of the valuable heavy particles through theexit-opening out'of the machine, where they are lost.

It is the object of myinvention to increase the efficiency, so as tomake the machine of practical utility and at the same time avoid theobjections above pointed out; also, to perform a part of theconcentration in the agitatingchamber. These objects I accomplish byproviding an agitating chamber with means whereby as the finely-dividedore is fed thereto the mass of material is continually thrown upward ina separated state, so that the air-blast can exercise its forcethereupon and start it up into the settling-chamber above, where theconcentrates readily settle under action of reduced air-currents and thelighter particles are carried off. By thus continually agitating andthrowingup the finely-divided ore I am enabled to use less forcibleblasts of air to carry the mass into Serial No. 732,320. (No man.)

bottom of the agitating-chamber, where they are conducted 01f into achute. The construction whereby these results are secured will be morefully set forth hereinafter and then definitely pointed out in theclaims.

In the drawings, Figure l is a sectional View of a machine embodying myinvention, some of the parts being shown in elevation. Fig. 2 is asimilar view showing a modifica tion wherein the throwing-blades aredriven from the side of the agitator, and Fig. 3 is a detail section ofa modified form of throwingblades.

The agitator-casing A, which may be of any desired form,but preferablyshown as two frusto-conical portions united at their bases, is suitablysupported on any usual or preferred framework B B C G. This casing formsan agitating-chamber A, enlarged at or near itsucentral portion topermit a proper circulation of air-currents therein prior to theirpassage into the exit-pipe a, which leads from said chamber into thesettling-chamber S above, wherein the heavyparticles are less influencedby the reduced air-currents, owing to the enlarged character of thesettling-chamher, and fall into the chute s, and thence from themachine. I have not deemed it necessary to further illustrate thesettlin'g-chan1-, ber S, as it forms no part of my present invention andis fully described in my pending application, Serial No. 730,841., filedSeptember 18, 1899.

It will be noted that the exit-pipe a extends through the casing A andwell into the agitating-chamber. This is for the purpose of preventing adirect passage of the air-ourrents from inlet b to and through the eXitpipe a, which would be the case if said pipe led direct from the top ofthe casing A. Moreover, by extending the pipe well into theagitating-chamber the end of the pipe is carried to a portion of theagitating-chamber where a zone of decreased air-pressu re andcirculating air-currents exists, which allow the heavy particles anopportunity to fall under theac-.

tion of gravity and gradually work to the bot-.

tom of the chamber, where they pass from am thus able to adjust saidpipe to different positions in the casing. The exit-pipe may also, ifdesired, have a sliding fit in the bottom of the settling-chamber S, asat 8 Near the side of the-casing A is suitably supported a feed-hopperD, which communicates with the chamber A by means of a feedconduit (1,in which works a feeding device, preferably in the form of a screw d,secured to or formed as part of a shaft (1 which may be driven by anysuitable means through the pulley d WVhile any other form of feedingdevice may be used, I prefer the feed-screw working in and fitting theconduit cl, for the reason that it effectually prevents the exit of anyair from the chamber even under high pressures.

Below the feeding device and preferably in the side of the casingopposite thereto is the air-inlet pipe b, communicating by suitableconnections I) with any usual source of air-blast-as the-fan Bforinstance. It will be noticed that the air-blast inlet b is locatedbelow the feeding device and for the reason that the blast of air isthus conducted to the chamber A at a point most effective in exertingits lifting effect upon the ore as it is fed to the machine.

The lower part of the casing A terminates in a reduced portion Aextending some distance below the agitating-chamber A. This extension orreduced portion A may be made in any suitable form; but I preferablymake it cylindrical in order to more easily adapt the throwing-blades atherein, as will presently appear. The bottom of the reduced portion Ais closed by a wall a having several slots 0. therein, and below thesaid bottom is the chute a terminating in a dischargespout a Extendingupward from the bottom wall a is the stud or pin a upon which the shafta is supported. This shaft also finds a suitable bearing at its upperend at a on the frame B and carries at its lower part thethrowing-blades a a These blades may be of any usual or desired form, soas by their revolution they will throw the material upward, and they maybe of the same or different size; but I prefer to make them asillustrated in Figs. 1 and 2-that is, the blades a that are within thereduced portion A are made to fit such portion, and those a above andextending into the agitating-chamber A, are made larger in order tothrow the material upward with increased force as the lower blades liftit from the reduced portion. I have found this form to giveexcellentres'ults, and by extending the upper blades into theagitating-chamber I secure a thorough agitation of the comminuted oreand secure a-complete disintegration of any mass that may become packedor caked together, while at the same time the material is thrown withsuch force that the incoming blast of air is enabled to lift theparticles in its passage through the exit -pipe into thesettling-chamber S. r

The stud or pin a is provided with a spiral groove a and the shaftpreferably has its lower end recessed to receive said stud or pin, bywhich it is supported. The grooves a serve to keep the bearing betweenthe shaft and pin or stud free from particles of sand and grit byworking said particles down the spiral grooves and out of the bearing.like provision is made near the upper end of the shaft a where it passesthrough the casing A. At this point an elongated sleeve a having flaringends a, is provided, and the shaft 0, has formed thereon a spiral groovea, which by the turning of the shaft keeps sand and grit from injuringor cutting the bearing-surface between the sleeve a and the shaft a Thesleeve a is preferably formed of light metal, and the ends thereof areflared outward from the shaft, so that the end within the casing willact to catch a certain amount of the moving air-currents, which will actas a cushion to prevent binding of the sleeve upon the shaft under thepressure of air in the agitating chamber, which is the case when thesleeve is made to closely fit around the shaft. If desired, both ends ofthe sleeve may be made alike, so that it can be reversed, though this isnot essential. Below the lower blades on the shaft are a series ofscrapers or arms a, which are located just above the bottom a of thecasing, and these arms serve to sweep any particles of heavy materialthat fall to the bottom of the reduced portion-A into the openings aleading to the chute a The shaft a is provided at or near its upper endwith a bevel-gear g, which, meshing with the bevel=gear g, carried bythe shaft Gr and driven by the pulley g from any source of power,transmits motion of rotation to the shaft a 'At one side of the reducedportion A a sliding door is provided at 75, which permits access to theinterior of the reduced portion when it-becomes desiralole.

In opposite walls of the casing A are the observation-windows L, throughwhich the operative can view the internal workings of the machine andregulate the feed of material thereto accordingly.

In Fig. 2 I have shown a modified form of means for driving the shaft awhich consists of the horizontal shaft G inclosed in a tubular brace Pand extending from the side of the easing into the agitating-chamber A.The braces P and P serve to support a yoke 19, in which the shafts G anda have bearings at p and 12 respectively. On the outer end of shaft G isthe pulley Q22, through which motion is imparted to said shaft andtransmitted therefrom through the bevelgears g and g to the shaft a aswill be obvious. It is necessary when this form of driving mechanism isemployed to prevent the gearsand bearings from becoming injuriouslyclogged by-fine particles of ore-sand, and to this end I employ the hoodp, preferably formed of sheet metal and completely housing the yoke 19,and thegears and bearings. This hood is provided at its portion thatencircles the shaft a with an elongated bearing 1J2, havin g the endthereof at p flared to form an air-cushion and prevent binding oftheiyielding metal of the hood against the shaft-f rl'The shaft at thepart that passes througlnthe bearing 19 has a spiral groove P ,Wl1lCh:prevents any dirt or grit from finding access to the interior of-the,hood, the

grooves serving to work all such matter outward as it revolves.

.In Fig. 3:1 have shown a modified form of throwing device wherein thehorizontal shaft m carries a series of fan-blades m working with a closeit in the reduced portion a of the casing. Below the throwing device isthe opening a for the exit of any heavy particles that find their waypast the throwing-blades m and extending from the casing is the chute aand exit-spouted. When this form of throwing device is employed,it isnecessary to provide a deflector m to direct mate rial to the rising orthrowing portion of the device.

In general the dimension of parts will be such that the diameter of theagitator at its greatest width will be from six to twenty times thediameter of the exit-pipe and its height from six to forty times thediameter of said pipe. These proportions may vary, of course, as mayalso the relative sizes of the throwing-blades.

The operation of the device is as follows: The finely ground or powderedore is fed into the hopper D and transmitted to the agitating-chamber bythe feed-screw. As it falls the air-blast passes through it, carryingaway some of the lighter particles through the exitpipe a into thesettling-chamber 8. As the mass falls it is acted on by the throwingblades, which separate and scatter the mass and throw it upward, wherethe blast acts to carry it into and through the exit-pipe. The air-blastentering the agitator does not pass direct to the exit-pipe a,butcirculates around in currents, partly due to the fact that the air-blastenters the chamber at an angle to the exit and that the exit-pipeextends well into the agitating-chamber. The circulation of thesecurrents affords opportunity for the heavier particles to fall, and someof them pass out through the slots in the bottom of the reduced portionA of the agitator, while others, with the light material, are carriedinto the settling chamber S, where the heavy and valuable portions ofthe mass entering enlarged above the throwing device, anexitpipe leadingfrom said chamber, a feeding device, an air-inlet for conducting a blastof air into said chamber below the feeding device and above the throwingdevice.

2. In an oreconcentrating agitator, the combination of a casing formingan agitatingchamber, a throwing device mounted in the lower part of saidchamber, the latter being enlarged above the throwing device, anexitpipe leading from the chamber and extending thereinto, means forfeeding ore to saidv chamber, and an air-inlet for conducting a blast ofair into said chamber below the feeding means, and below the lower endof the exit-opening.

3. In an ore-concentrating agitator, thecombination of a casing havingan enlarged central portion forming an agitating-chamher, a throwingdevice mounted in the lower part of said chamber for throwing materialupward, an exit-pipe for the lighter particles of ore leading from andextending into said chamber, means for feeding ore to said chamber,means for creating an air-blast and an inlet for conducting the blast ofairinto said chamber below the feeding means.

4:. In an ore concentrating agitator, the combination of a casing havingan enlarged central portion forming an agitating-chamber, a throwingdevice mounted in the lower part of said chamber for throwing materialupward, a discharge-chute below said throwing device, and formingpractically a closed bottom for the casing, an exit-pipe leading fromand extending into said chamber oppo site the said throwing device, afeeder and an air-inlet for conducting a blast of airinto said chamberbelow the feeder.

5. In an ore concentrating agitator, the combination of a casing havingan enlarged portion forming an agitating-chamber and provided with areduced and practicallyclosed lower portion, a throwing devicecomprising a series of revolving blades practically occupying thecross-area of the lower portion, an exit-pipe leading from said chamber,a feeder and an air-inlet for conducting a blast of air into saidchamber below the feeder.

6. The combination of a casing forming an agitating-chamber, having anenlarged central portion and a reduced bottom portion, a throwing devicecomprising a revolving shaft having a series of blades occupying saidreduced portion and extending upward into the iii;

enlarged portion, an exit-pipe for the light,

material, a feeder and an air-blast inlet below the exit-opening.

7. A casing having an enlarged central portion andla reduced lowerportion constituting a chamber for the rarefaction and recondensation ofthe ascending air-currents,,an

exit in the upper part of the chamber for the lighter particles of ore,an air-blast inlet leading into the chamber below the exit-opening,

, a feeder above the air-blast inlet, and a re.-

volving shaft with agitating-blades located in the reduced lower portionof the chamber and extending up into the enlarged central portionthereof, said blades in the central portion being of increased length.

8. In an ore-concentrating agitator, the combination of a casing havingan enlarged central portion constituting an agitatingchamber, anexit-pipe leading from said chainber and extending thereinto, a throwingdevice in the lowerpart of said chamber, a feeder, an air inlet forconducting a blast of airinto said chamber below the feeder and abovethe throwing device and a door in the lower part of the casing oppositethe throwing device.

9. loan ore-concentrating agitator, the

combination of a casing forming anagitating-chamber, and having areduced lower portion, a stud projecting upward from the bottom of thesaid lower portion, a shaft inlet leading to said chamber from the sidethereof and below the feeding device to prodime a circulation ofair-currents in the agitating-chamber, and an exit-pipe fittedadjustablyinto the casing whereby it may be extended more or less into the saidagitatingchamber.

ALBERT H. STEBBINS.

Witnesses:

W. B. WALTHEN, R. G, PILLOW.

